How do I use cpio command under Unix?

Q. Can you explain how do I use cpio under Linux / UNIX?

A. GNU cpio is a tool for creating and extracting archives, or copying files from one place to another. It handles a number of cpio formats as well as reading and writing tar files. cpio command works just like tar, only better.

As I said earlier, cpio works like tar but it can read input from the "find" command. This is nifty feature. For example you can find out all *.c files and backup with cpio command.

# find / -name "*.c" | cpio -o --format=tar > c-file.backup.tar
# find / -iname "*.pl" | cpio -o -H tar > perl-files.tar

You can also specify file name using -F option:

# find / -iname "*.pl" | cpio -o -H tar -F perl-files.tar

Where,

-o: Create archive
-F: Archive filename to use instead of standard input or output. To use a tape drive on another machine as the archive.
-H format: Specify file format to use.
-i: Restore archive

You can extract archive with the following command:

# cpio -i -F perl-files.tar

You can list file inside archive i.e. list contents of the cpio file with following command:

# cpio -it -F perl-files.tar

You can write archive of /home to tape (drive /dev/nst0), type the following command:

# find /home | cpio -o -H tar -F /dev/nst0

Restore backup using following command:

# cpio -i -F /dev/nst0Backup /home dir,

to remote system tape drive:
# find /home | cpio -o -H tar -F user@backup.nixcraft.in:/dev/nst0 --rsh-command=/usr/bin/ssh